967 resultados para Alain Grandbois
Resumo:
Individual recognition systems require the sender to be individually distinctive and the receiver to be able to perceive differences between individuals and react accordingly. Many studies have demonstrated that acoustic signals of almost any species contain individualized information. However, fewer studies have tested experimentally if those signals are used for individual recognition by potential receivers. While laboratory studies using zebra finches have shown that fledglings recognize their parents by their “distance call”, mutual recognition using the same call type has not been demonstrated yet. In a laboratory study with zebra finches, we first quantified between-individual acoustic variation in distance calls of fledglings. In a second step, we tested recognition of fledgling calls by parents using playback experiments. With a discriminant function analysis, we show that individuals are highly distinctive and most measured parameters show very high potential to encode for individuality. The response pattern of zebra finch parents shows that they do react to calls of fledglings, however they do not distinguish between own and unfamiliar offspring, despite individual distinctiveness. This finding is interesting in light of the observation of a high percentage of misdirected feedings in our communal breeding aviaries. Our results demonstrate the importance of adopting a receiver's perspective and suggest that variation in fledgling contact calls might not be used in individual recognition of offspring.
Resumo:
The purpose of this study was to evaluate safety and efficacy of the Solitaire FR device in the treatment of patients with acute ischemic stroke secondary to large artery occlusion.
Resumo:
The aim of this study was to evaluate the accuracy of dual-echo (DE) magnetic resonance imaging (MRI) with and without fat and water separation for the quantification of liver fat content (LFC) in vitro and in patients undergoing liver surgery, with comparison to histopathologic analysis.
Resumo:
The majority of Crohn's disease patients will develop a complicated disease course over time which is characterized by the occurrence of stricturing and penetrating disease. Penetrating disease comprises internal fistulas (e.g. enteroenteric) and perianal disease. A complicated disease course may be associated with considerable morbidity and professional and personal disabilities. Treatment options for fibrostenotic Crohn's disease comprise endoscopic balloon dilation, stricturoplasties and surgical resection. Treatment of symptomatic perianal fistulizing disease is based on antibiotics, immunomodulators and anti-TNF drugs. Surgical measures include fistula drainage by means of setons, temporary ileostomy or a proctectomy. The presence of internal fistulas often necessitates surgical measures. A close collaboration between the gastroenterologist and the surgeon is mandatory to solve these interdisciplinary challenges.
Resumo:
Although systemic corticosteroids are successfully administered for the induction of clinical response and remission in the majority of patients with inflammatory bowel disease (IBD) presenting with a flare, a proportion of these patients demonstrate a primary nonresponse to steroids or in the case of an initial response, they develop a resistance or a steroid dependence. Long-term therapy with corticosteroids for treatment of IBD should be avoided, given the high frequency of adverse treatment effects. Knowledge about treatment strategies in case of steroid nonresponse is therefore highly relevant.
Resumo:
Medical therapy of inflammatory bowel disease (IBD) is becoming more complex, given the increasing choice of drugs to treat Crohn's disease (CD) and ulcerative colitis (UC). We aimed to summarize the current guidelines for first-line treatments in IBD.